Re: [Qemu-devel] [PATCH v2] ACPI: Fix AppleSMC _STA size

["Michael S. Tsirkin" <mst@redhat.com>]

On Mon, Jan 13, 2014 at 03:27:13PM -0500, Gabriel L. Somlo wrote:
> Minimize the storage used for AppleSMC's _STA (8bit), relying on ASL
> to implicitly convert it to the officially specified 32bit value.
> 
> Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
> ---
> 
> This applies incrementally on top of "Add DSDT node for AppleSMC" v.3
> (accepted Dec. 25, 2013), and obsoletes everything I've sent out since :)
> 
> After some experimentation I realized ASL is flexible about the size of
> its named variables, and happy to implicitly convert an 8bit value to
> 32 bits when needed. As such, I vote for the space saving option...
> 
> Thanks, and sorry for all the noise,
>   Gabriel


Applied, thanks.

>  hw/i386/acpi-dsdt-isa.dsl |  4 ++--
>  hw/i386/acpi-build.c      | 11 +++++------
>  2 files changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/i386/acpi-dsdt-isa.dsl b/hw/i386/acpi-dsdt-isa.dsl
> index 46942c1..3a6e100 100644
> --- a/hw/i386/acpi-dsdt-isa.dsl
> +++ b/hw/i386/acpi-dsdt-isa.dsl
> @@ -19,8 +19,8 @@ Scope(\_SB.PCI0.ISA) {
>      Device (SMC) {
>          Name(_HID, EisaId("APP0001"))
>          /* _STA will be patched to 0x0B if AppleSMC is present */
> -        ACPI_EXTRACT_NAME_WORD_CONST DSDT_APPLESMC_STA
> -        Name(_STA, 0xFF00)
> +        ACPI_EXTRACT_NAME_BYTE_CONST DSDT_APPLESMC_STA
> +        Name(_STA, 0xF0)
>          Name(_CRS, ResourceTemplate () {
>              IO (Decode16, 0x0300, 0x0300, 0x01, 0x20)
>              IRQNoFlags() { 6 }
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 30bfcd2..9e5733e 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -81,7 +81,7 @@ typedef struct AcpiMiscInfo {
>  
>  static void acpi_get_dsdt(AcpiMiscInfo *info)
>  {
> -    unsigned short applesmc_sta_val, *applesmc_sta_off;
> +    uint16_t *applesmc_sta;
>      Object *piix = piix4_pm_find();
>      Object *lpc = ich9_lpc_find();
>      assert(!!piix != !!lpc);
> @@ -89,18 +89,17 @@ static void acpi_get_dsdt(AcpiMiscInfo *info)
>      if (piix) {
>          info->dsdt_code = AcpiDsdtAmlCode;
>          info->dsdt_size = sizeof AcpiDsdtAmlCode;
> -        applesmc_sta_off = piix_dsdt_applesmc_sta;
> +        applesmc_sta = piix_dsdt_applesmc_sta;
>      }
>      if (lpc) {
>          info->dsdt_code = Q35AcpiDsdtAmlCode;
>          info->dsdt_size = sizeof Q35AcpiDsdtAmlCode;
> -        applesmc_sta_off = q35_dsdt_applesmc_sta;
> +        applesmc_sta = q35_dsdt_applesmc_sta;
>      }
>  
>      /* Patch in appropriate value for AppleSMC _STA */
> -    applesmc_sta_val = applesmc_find() ? 0x0b : 0x00;
> -    *(uint16_t *)(info->dsdt_code + *applesmc_sta_off) =
> -        cpu_to_le16(applesmc_sta_val);
> +    *(uint8_t *)(info->dsdt_code + *applesmc_sta) =
> +        applesmc_find() ? 0x0b : 0x00;
>  }
>  
>  static
> -- 
> 1.8.1.4